This invention relates to derivatives of catechins and methods for preparing same. In one aspect, the invention relates to biocidal compositions including sulfide derivatives of catechins, particularly epicatechins, derived from condensed tannin as the active ingredient.
Catechin, epicatechin and certain derivatives of catechin and epicatechin are known to possess pharmaceutical and/or viricidal properties. For example, U.S. Pat. No. 4,460,578 discloses that the extract from Hedysarum fructescens willd consisting of a combination of flavonoids, catechin, tannins and phenol acids is effective for the treatment of tegumentary virus infections. U.S. Pat. No. 4,248,789 discloses that catechins derived from tannin extracted from tea leaves have a viricidal effect. U.S. Pat. No. 4,166,861 discloses that epicatechin and ketal and esters of catechin and epicatechin have a choleretic, hypocholesterolimic, hypolipaemic and hepatoprotective effect. U.S. Pat. No. 3,888,990 discloses that sulfonic acid derivatives of epicatechin are effective in the treatment of vascular diseases and conjunctive tissue disorders. Examples of other flavonoid extracts are disclosed in U.S. Pat. Nos. 3,928,585 and 3,270,003.
Applicant has found that sulfide derivatives of catechins, particularly epicatechins, derived from condensed tannin have biocidal characteristics.